Nisbett points to newer data collected in the past year that would suggest the possibility of change at a young age. "I'm certainly not an essentialist in that I think that these differences are genetic . . . and I'm not an essentialist in that I think these things aren't changeable. We don't know at what point these differences become ingrained, and we don't even know how fixed they are in being ingrained."

You'd be forgiven for regarding Nisbett's conclusions with a wary eye. On the surface, they run counter to the conventions about human difference we would like to believe, particularly at a time when culture and nation are misread as a difference that can only be reconciled by violence. Universalism is goodit sounds fair, bears no grudges, and offers a hopeful understanding of the world. What if it's just a fiction?

Nisbett himself was worried that his work would be interpreted as something that condemned, rather than celebrated, human difference. "Universalism is kind of a religion," he explains. "It wasn't just that I had a deep intellectual conviction; it was really a religion for me that we were all the same. It was very important. But if we are really different, we ought to know that. Otherwise, we can attribute difference to the other person being a jerk, or to them belonging to a group that's inferior in some way."

illustration: Suzanne Allen

Ever since Samuel Huntington's jarring Clash of Civilizations (1996) recast the seemingly peaceful post-Cold War world as an array of rigid, potentially antagonistic cultures, there has been a heightened interest in acknowledging, explaining, and understanding the world's differences. In particular, recent books like Kishore Mahbubani's Can Asians Think?, William Hannas's The Writing on the Wall: How Asian Orthography Curbs Creativity (2003), and C. Fred Alford's Think No Evil: Korean Values in the Age of Globalization (1999) have fixed on that nebulous space dividing Asian and American. Though Nisbett's book glosses over some of the obvious historical or linguistic reasons separating Asian and Western thoughtand though it invests itself in a simplistic promise of even cross-cultural exchangeit's a vital contribution to the discussion of how humans differ and how they can get along in spite of those differences.

I spoke to Nisbett the day before the war on Iraq officially began and we wondered aloud whether this was an appropriate time to ditch universalism. Interspersed among Geography's flat details of theory and experimentation, you read Nisbett himself struggling with his conclusions, and you eventually find him relinquishing one kind of hope for another. "Now that I know that we're different, my crusade is a little different," he explains. He closes the book with an inspired call for a more humane globalism, one that departs from foundational differences but aspires toward universal values and compassion.

"It's a little harder to believe [in convergence] today than it was four or five months ago," Nisbett says. "It doesn't seem quite so likely today." He pauses, considering the weight of his words. "That's the hopeful conclusion."